DNS
THE CERTIFICATE BEHIND THE CONNECTION

TLS certificate checker.

Inspect SSL/TLS certificates for any public domain or subdomain.

Checks HTTPS on port 443, including subject alternative names, validity dates and the presented chain.

SSL certificate

TLSv1.3

ok.ac.kr · 203.232.140.89:443

Verified

Certificate chain, hostname and dates verified using this server’s CA store.

Subject
C=KR ST=Chungcheongbuk-do L=Cheongju-si O=CHUNG CHEONG UNIVERSITY CN=*.ok.ac.kr
Issuer
C=US O=DigiCert Inc CN=DigiCert Global G2 TLS RSA SHA256 2020 CA1
Valid from
2026-05-22T00:00:00+00:00
Expires
2026-12-06T23:59:59+00:00
Days remaining
47
Serial (hex)
069369D1137FB78538FD017C95F68DCF
Signature
RSA-SHA256
Public key
RSA 2048

Subject alternative names (SAN)

DNS:*.ok.ac.kr, DNS:ok.ac.kr

SHA-256 fingerprint

71:7E:64:BA:E4:EA:A6:B7:24:29:C4:66:50:5C:CA:2D:28:8F:F8:90:DC:A1:CC:C9:7D:0C:3F:A0:CC:64:F2:64
Certificate extensions & PEM
authorityKeyIdentifier
74:85:80:C0:66:C7:DF:37:DE:CF:BD:29:37:AA:03:1D:BE:ED:CD:17
subjectKeyIdentifier
23:AA:F5:FD:C8:9E:FD:63:B2:39:5A:8C:30:FF:76:9C:62:7A:4E:9E
subjectAltName
DNS:*.ok.ac.kr, DNS:ok.ac.kr
certificatePolicies
Policy: 2.23.140.1.2.2 CPS: http://www.digicert.com/CPS
keyUsage
Digital Signature, Key Encipherment
extendedKeyUsage
TLS Web Server Authentication, TLS Web Client Authentication
crlDistributionPoints
Full Name: URI:http://crl3.digicert.com/DigiCertGlobalG2TLSRSASHA2562020CA1-1.crl Full Name: URI:http://crl4.digicert.com/DigiCertGlobalG2TLSRSASHA2562020CA1-1.crl
authorityInfoAccess
OCSP - URI:http://ocsp.digicert.com CA Issuers - URI:http://cacerts.digicert.com/DigiCertGlobalG2TLSRSASHA2562020CA1-1.crt
basicConstraints
CA:FALSE
ct_precert_scts
Signed Certificate Timestamp: Version : v1 (0x0) Log ID : C2:31:7E:57:45:19:A3:45:EE:7F:38:DE:B2:90:41:EB: C7:C2:21:5A:22:BF:7F:D5:B5:AD:76:9A:D9:0E:52:CD Timestamp : May 22 02:13:35.478 2026 GMT Extensions: none Signature : ecdsa-with-SHA256 30:46:02:21:00:BB:BD:92:80:DE:66:2B:C3:2F:01:D5: A4:01:96:01:49:F4:FD:B8:71:52:F9:82:2B:7D:B2:9B: 80:59:7A:65:E3:02:21:00:86:7D:CB:F3:07:88:1B:E6: 28:8C:86:ED:CA:FF:62:79:C7:8E:42:AE:29:18:03:F8: F5:DB:E2:FF:AB:E8:75:67 Signed Certificate Timestamp: Version : v1 (0x0) Log ID : D7:6D:7D:10:D1:A7:F5:77:C2:C7:E9:5F:D7:00:BF:F9: 82:C9:33:5A:65:E1:D0:B3:01:73:17:C0:C8:C5:69:77 Timestamp : May 22 02:13:35.473 2026 GMT Extensions: none Signature : ecdsa-with-SHA256 30:46:02:21:00:8D:04:27:6E:83:BB:35:53:24:4E:0E: 10:56:0B:D8:04:A4:52:B3:7B:FD:2B:78:1B:25:21:DF: 3A:2D:C3:67:62:02:21:00:D6:D2:5B:2F:B5:A0:51:72: EF:ED:B9:E5:6B:55:36:46:46:27:0D:F3:DD:86:74:43: 5B:5F:2C:CC:5E:27:EC:5F Signed Certificate Timestamp: Version : v1 (0x0) Log ID : 94:4E:43:87:FA:EC:C1:EF:81:F3:19:24:26:A8:18:65: 01:C7:D3:5F:38:02:01:3F:72:67:7D:55:37:2E:19:D8 Timestamp : May 22 02:13:35.498 2026 GMT Extensions: none Signature : ecdsa-with-SHA256 30:45:02:20:20:F2:79:1F:6C:E3:94:0E:75:55:D1:82: 14:D3:5F:0E:5A:FC:31:BC:14:42:B9:B6:B8:22:16:3A: 98:35:B2:77:02:21:00:FF:99:14:0B:D9:17:B6:67:57: BF:67:07:BA:E1:E1:CA:AB:72:81:05:58:3A:A8:A4:E3: F4:D5:3C:D7:5C:2E:77
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Cipher: TLS_AES_256_GCM_SHA384 · Checked 2026-10-20T09:29:09+00:00

Server-presented chain · 2 additional certificates

Chain certificate 1

Subject
C=US O=DigiCert Inc OU=www.digicert.com CN=DigiCert Global Root G2
Issuer
C=US O=DigiCert Inc OU=www.digicert.com CN=DigiCert Global Root G2
Valid from
2013-08-01T12:00:00+00:00
Expires
2038-01-15T12:00:00+00:00
Days remaining
4105
Serial (hex)
033AF1E6A711A9A0BB2864B11D09FAE5
Signature
RSA-SHA256
Public key
RSA 2048

Subject alternative names (SAN)

No SAN extension was presented.

SHA-256 fingerprint

CB:3C:CB:B7:60:31:E5:E0:13:8F:8D:D3:9A:23:F9:DE:47:FF:C3:5E:43:C1:14:4C:EA:27:D4:6A:5A:B1:CB:5F
Certificate extensions & PEM
basicConstraints
CA:TRUE
keyUsage
Digital Signature, Certificate Sign, CRL Sign
subjectKeyIdentifier
4E:22:54:20:18:95:E6:E3:6E:E6:0F:FA:FA:B9:12:ED:06:17:8F:39
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Chain certificate 2

Subject
C=US O=DigiCert Inc CN=DigiCert Global G2 TLS RSA SHA256 2020 CA1
Issuer
C=US O=DigiCert Inc OU=www.digicert.com CN=DigiCert Global Root G2
Valid from
2020-09-24T00:00:00+00:00
Expires
2030-09-23T23:59:59+00:00
Days remaining
1434
Serial (hex)
085F94C02D857BE8CC14FF53EDA23E2A
Signature
RSA-SHA256
Public key
RSA 2048

Subject alternative names (SAN)

No SAN extension was presented.

SHA-256 fingerprint

1F:8E:B9:E9:A8:E0:66:CC:5B:38:33:E0:6B:31:29:76:4B:62:26:39:D5:B1:63:F6:00:E1:C7:91:20:BF:3E:ED
Certificate extensions & PEM
subjectKeyIdentifier
74:85:80:C0:66:C7:DF:37:DE:CF:BD:29:37:AA:03:1D:BE:ED:CD:17
authorityKeyIdentifier
4E:22:54:20:18:95:E6:E3:6E:E6:0F:FA:FA:B9:12:ED:06:17:8F:39
keyUsage
Digital Signature, Certificate Sign, CRL Sign
extendedKeyUsage
TLS Web Server Authentication, TLS Web Client Authentication
basicConstraints
CA:TRUE, pathlen:0
authorityInfoAccess
OCSP - URI:http://ocsp.digicert.com CA Issuers - URI:http://cacerts.digicert.com/DigiCertGlobalRootG2.crt
crlDistributionPoints
Full Name: URI:http://crl3.digicert.com/DigiCertGlobalRootG2.crl Full Name: URI:http://crl4.digicert.com/DigiCertGlobalRootG2.crl
certificatePolicies
Policy: 2.23.140.1.1 Policy: 2.23.140.1.2.1 Policy: 2.23.140.1.2.2 Policy: 2.23.140.1.2.3
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

One endpoint on port 443. Server-presented chain; no revocation, OCSP, CT or full TLS security scan.

View certificate JSON

Registration / WHOIS →DNS records →